In a common television (TV) system, noise processing is performed on an image data (e.g., a frame data or a field data) to adjust luminance values of the image data, and the adjusted image data is further processed and displayed on a TV display. However, during the noise processing, a same noise processing approach is applied on each pixel of the image data; that is, regardless of complexity on details of various blocks, e.g., blocks with complicated details (such as lawns or leaves) in the image or blocks with simple details (such as the sky or the skin of a person) in the image, a same noise processing level is used. Accordingly, when high-level noise processing is used, the area having complicated details is excessively processed such that image details become too obscure to be displayed. When low-degree noise processing is used, the noise processing may be unsatisfactory for blocks with simple details, such that noise is not effectively restrained to undesirably affect image quality.